worthwhile putting a 2.0 into a 3500 lb '85 Monte Carlo?

[MetroMPG]

Received this question at metrompg.com...

I would like to know what possibile mpg goal there is for putting a very small engine in a larger car. Even if you only get 35mpg, that is still better than any 3500lb car is getting now. I want to know if it is even worth the trouble to put a 2.0L (85hp) engine in a 1985 Monte Carlo.

The writer originally wanted to know if I'd test my car by adding a lot of weight to see what happens to the fuel consumption - as a point of reference.

I would say the Prius is an example of a "small" engine in a larger car, and it gets great mileage on the highway, even when the EV systems aren't contributing.

Of course it's a wee bit more aerodynamic than an '85 Monte Carlo...

And the Prius is an Atkinson ICE...

Any other examples?

I read somewhere that in some east Asian markets, Mercedes sells versions of its S Class with a 2.0L due to local regulations.

[VetteOwner]

hmm well, i have a 2.2L in my s-10, which is almost 4,000 lbs... and it gets up and goes pretty good. i got 27 mpg last fill up. its prolyl in the 30's somehwere on the interstates. and its about as aerodynamic as a monte... but mine is geared for tourqe and hauling/towing. so if you get the right tranny, it could see 30+ on a regular basis.

they used to put 4 banger engines from the factory in dodge darts i thought...

if the car doesnt run, and you got a few thousand to spend, and you already have a running 4 banger id say go for it. its gonna accelerate liek a dump truck but once its going it would be fine. if you find a 4 banger with a carb it would make your life oh so much easier.

but to do it heres a crude list of stuff you will need:
engine*
tranny
custom driveshaft
custom motor mounts
custom tranny mount
flexable radiator hoses
some way to link the auto shifter to the new tranny
new speedo gear
might have to change throttle cable


theres no doubt that it WILL fit in that engine comaprtment and exhaust stuff will have plenty of clearance.


*carberated engine, with a modern FI engine its gonna be a PITA to hook up all that computer stuff.

[kickflipjr]

My first question would be what mpg is the Monty Carlo getting currently and what size is the current engine.

I don't think it he get 35mpg with it (especially if it is an auto tranny). Having said all that I would say go for swap.

[CoyoteX]

I think he might pick up at best 5mpg. This would be if he doesn't modify his driving style and try driving slower. It takes a certain amount of energy to get up to speed and fight the wind resistance. That is always going to take a certain amount of gas. So if he goes to a 3 cyl metro motor he might get better mileage since he won't be able to go as fast or accelerate as fast

Kind of like the work I do to my car, I improve it and get better mileage then typically I start driving faster/accelerating harder and eat into my mileage improvements. He can improve his car by putting in a smaller engine, but unless he modifies his driving to take advantage of the changes it really won't change a lot.

[unstable bob]

Originally Posted by VetteOwner

they used to put 4 banger engines from the factory in dodge darts i thought...

Dodge Darts only came with 6 cylinders and V8s from the factory.

[omgwtfbyobbq]

Loaded, the Camry comes in at ~3500-4300lbs depending on how many are in it and what cargo there is, and it's at ~35mpg@55mph stock. What's needed is the combo of gearing/displacement that'll allow for the best mileage at whatever speeds the person travels as well as acceptable acceleration in that gear, or one gear down, depending on opinion. Imo, if it's a custom jobby, might as well just drop in suitable gearing instead, that way the driver can have best of both worlds. The only time I would go with an engine that small in a car that big would be a dedicated citi-car.

[skewbe]

That pig don't sing

[Bill in Houston]

35 mpg seems like an awful lot. If he uses the mileage vs speed calculator on your site, what kind of efficiency would he have to get to in order to get 35 mpg?

Another data point. Our 1975 Volvo weighed less than 3500 lbs, has a 2 liter engine, and got maybe 25 mpg on the highway. He's gonna need a really good 2 liter engine and transmission, not just whatever he can find...

What's the biggest car you could get with a 4-cylinder recently in the US? A Taurus? A 1st generation Honda Odyssey? How did they do on the highway?

Okay, I'll stop asking questions. :-)

[brucepick]

I'd put the time and money into aero work.

And definitely improve driving technique.

Air dam project below cost $30 for plastic, one roll duct tape, and an aluminum carpet edge strip about $10. Granted that's not the only mpg project I've done on this car but I expect 45% over the EPA estimates based on recent fillup data.



One can take this further with a better grill/headlight treatment, side skirts, wheelwell skirts, and underbody aero coverings - not necessarily in that order.

Basjoos is getting something like 120% or more over EPA with his rig and I think his mods are all aero, plus driving technique of course. But with his aero work he apparently can go quite fast with little or no drag penalty.

My car is 3030 lb, 115 hp 2.3 liters, fuel injected, elec ign. At that weight power was just adequate before starting mods. With 2.0 liters I think it would be a truly slow pig unless it had some serious engine mods.

[OdieTurbo]

Originally Posted by VetteOwner

If the car doesnt run, and you got a few thousand to spend, and you already have a running 4 banger id say go for it. its gonna accelerate liek a dump truck but once its going it would be fine. if you find a 4 banger with a carb it would make your life oh so much easier.

but to do it heres a crude list of stuff you will need:
engine*
tranny
custom driveshaft
custom motor mounts
custom tranny mount
flexable radiator hoses
some way to link the auto shifter to the new tranny
new speedo gear
might have to change throttle cable

theres no doubt that it WILL fit in that engine comaprtment and exhaust stuff will have plenty of clearance.

Dude! You must not have ever worked on a Monte Carlo. They come stock with either a 3.8L V6 or a 5.0L V8. To swap in an S-10 4 cylinder it would be a direct bolt-in replacement. Just need to tweak your radiator hoses, get a computer from the S-10 and put in some different front springs.

And I doubt it would cost thousands. Hell, if I still had the tools, I'd throw it in for $300.

As to any gains he might get.... I'd take the $300 and go buy a cheat beat-up corolla.